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How is the complex conjugate of a complex number obtained?
AFlip the sign of the real part
BFlip the signs of both parts
CSwap the real and imaginary parts
DFlip the sign of the imaginary part
Answer & Solution
Correct answer: D. Flip the sign of the imaginary part
1. The conjugate is built so that the product with the original is a real number.
2. It is found by changing the sign of the imaginary part and leaving the real part unchanged.
3. So the conjugate of 3 + 5i is 3 - 5i.
4. Changing the real part instead would not clear the imaginary term from a denominator.
_Source: OpenStax Precalculus (CC BY 4.0), section 3.1 Complex Numbers_
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